The present invention relates to a reverse gear involuntary articulation inhibitor device for external commands of automobiles speed gears. More precisely, the invention relates to an inhibitor device of the type comprising a bolt consisting of the gear lever and an inhibitor lock consisting of the lever fixed articulation and in which the bolt, supported on an axially movable tube relative to the lever, is displaceable for surpassing the inhibitor lock and allow the reverse gear articulation.
In general, in the external commands of automobile speed gears, the gears selection and articulation is made according to FIG. 1 referring to a command for a five-relation gear, plus the reverse gear.
According to this prevailing adoption scheme, the first and second gears are opposed and aligned in correspondence to a shift plane which is located on the left side (referring to the scheme) of the central position, or dead point of the gear level, the third and fourth gears are opposed and aligned in correspondence to a shift plane which passes by the central position and the fifth gear is opposed to the reverse gear and aligned with it in a shift plane disposed on the right side of said central position.
The inhibitor lock is essentially for preventing the reverse gear involuntary articulation, mainly when the gear is chosen passing from the fifth to the fourth gear or, more generally when this latter gear is inserted from a dead point provisional position, procedure which is often made by inexperienced drivers, for example, on an incline. For this purpose, in known dispositions, the lock consists in a small fixed block of rigid material, provided with an opposition inclined plane which, during the disarticulation procedure of the fifth gear, secures a corresponding and conjugate inclined plane of the bolt associated to the lever for preventing the straight displacement corresponding to the reverse gear articulation and for deviating the lever itself towards the central articulation plan, according to a substantially coiled travel, in order to facilitate the fourth gear shift; the reverse gear shift is only possible by means of the voluntary lifting of the bolt and by the consequent release of this inhibitor lock bolt. However, if the passage from the fifth to the fourth gear is carried out quickly, the driver notices the unpleasant crash of the bolt with the inhibitor lock and, if the lever is firmly hold instead of being pushed so as to be opposed to the free displacement, according to the above mentioned coiled travel, there may usually occur the bolt jamming against the inhibitor lock with the consequent blockage of the fourth gear articulation procedure.
The present invention is intended to eliminate these and other drawbacks and, within this general purpose scope, it has the important purpose to improve said reverse gear inhibitor devices in order to substantially improve the movement capacity of the gear lever and increase the command reliability, eliminating locking possibility in case of an incorrect maneuver carried out by inexperienced drivers.
According to the present invention, these and other important purposes are realized by means of a reverse gear involuntary shift inhibitor device, having its features specified according to the claims below.
The invention is substantially based on the concept of securing the inhibitor lock in rotating and not fixed fashion, and subject it to the action of an elastic means which applies, to said lock, a moment which tends to distance the inclined plane of said lock from the bolt corresponding conjugate inclined plane travel.
Thus, as it will be evident from the following description, when correctly passing from the fifth to the fourth gear, the contact between the bolt and the inhibitor lock is practically eliminated, thanks to this lock separation from the bolt travel by means of said elastic means action.
Therefore, the above mentioned crash sensation, which is felt in the lever during the maneuver thereof, specifically when said movement is carried out quickly, is eliminated.
According to a preferred embodiment of the invention, the rotating inhibitor lock consists of an oscillating lever [a lever in closed square] according to an axis which is located in a substantially parallel plane to the central shift plane. This lever [in square] comprises a lower arm extending in a substantially orthogonal direction towards said central articulation plane and shows the opposition inclined plane cooperating with the corresponding lever bolt conjugate plane, and an upper arm extending substantially parallel towards the central articulation arm. Over the upper arm, there acts an impulse finger which is interdependent in the bolt tube and able to oppose said elastic means force acting on the lock. Like this, the gear lever movement occurs incorrectly, that is to say, not following said coiled travel, said impulse finger, acting on the inhibitor lock, prevents the rotation thereof induced by the elastic means, so that the opposition inclined plane remains in the bolt interception position thus preventing, by the bolt jamming, the reverse gear involuntary shift. The improved device features, purpose and advantages, according to the present invention, become evident from the following detailed description and with reference to the attached drawings, provided as non limiting example, in which.